King's Highway 403 is a major freeway route through Southern Ontario, connecting Mississauga to Woodstock, via
Hamilton and Brantford. Highway 403 offers motorists a more southerly alternative to Highway 401 and also forms a more direct route to Toronto via the
Queen Elizabeth Way from Southwestern Ontario. The highway was completed in several stages between 1963 and 1997, spanning a period of almost 35 years.
However, conceptual planning for the new highway actually began in the 1930s.

The approximate route of the road that would eventually become today's Highway 403 was first shown on a conceptual dual highways plan dated 1937, prepared
by the Ontario Department of Highways (DHO). While the concept of a divided highway from Hamilton to London was certainly an enticing idea, there were
other important highway construction projects that were already underway at that time which took priority. The DHO was especially concerned about
completing the Queen Elizabeth Way from Hamilton to Niagara Falls and Fort Erie. In 1938, shortly before the outbreak of World War II, surveyors were busy
at work in the Dundas area, identifying potential routes for the new dual highway. A survey plan prepared by the DHO in 1939 shows a conceptual route for a
new highway, identified as a "Proposed Diversion of Highway 2", which roughly paralleled the Governor's Road (Highway 99). The outbreak of World War II
further delayed construction of the new divided highway from Hamilton to London. After the War's conclusion, building materials were scarce due to supply
disruptions and Post-War reconstruction efforts. As Post-War highway construction priorities were reviewed by the DHO in 1945, it was decided that the
completion of the Toronto to Barrie Highway (today's Highway 400) and Highway 401 (then known as Highway 2A) from Toronto to Oshawa would be built first.

The first construction contract for Highway 403 was finally awarded in 1955, nearly 20 years after the concept of a dual highway from Hamilton to London
was initially proposed. The first construction contract for Highway 403 was actually tied to the relocation of the Queen Elizabeth Way on the north
approach to the Burlington Skyway. A new directional interchange was constructed on the relocated Queen Elizabeth Way at Freeman in 1956-1957, bypassing
the original 1937 Burlington Interchange at Plains Road. The new Freeman Interchange permitted a high-speed freeway-to-freeway connection with the proposed
Highway 403, which was finally getting off of the drawing board. For the first few years of operation, the Freeman Interchange only served the Queen
Elizabeth Way. The ramps connecting to the future Highway 403 sat silently in a field. In late 1960, the first construction contracts were awarded for the
construction of Highway 403 from the Freeman Interchange to Ancaster. The first phase of Highway 403 was completed and opened to traffic from the Queen
Elizabeth Way at Freeman to the Desjardins Canal Bridge in Hamilton on December 4, 1963. The second phase of Highway 403 was completed and opened to
traffic on July 9, 1965, from the Desjardins Canal Bridge to Aberdeen Avenue. The completion of Highway 403 to Aberdeen Avenue permitted uninterrupted
freeway access into Downtown Hamilton, greatly easing traffic congestion on adjacent Highway 2 and Highway 6. By the end of 1965, Highway 403 was 13 km in
length. In 1966, construction began on the most complicated section of Highway 403. The section between Aberdeen Avenue and Highway 2 west of Ancaster
involved an impressive new mountain access up the Niagara Escarpment. This new highway connection was needed to help take the pressure off of Highway 2 and
Hamilton's existing mid-town mountain access roads. The final section of Highway 403 through Hamilton was completed and opened to traffic between Aberdeen
Aveneue and Highway 2 (Wilson Street) on August 22, 1969, adding another 11 km to the length of the highway.

During the 1960s, another key section of Highway 403 was constructed through Brantford. In 1961, DHO surveyors identified and finalized a corridor across
the northern edge of Brantford for the proposed Brantford Bypass. This was one of the most important sections of proposed Highway 403, as the city was a
bottleneck for through traffic on Highway 2 and Highway 53. Construction began on the Brantford Bypass in 1963. On October 31, 1966, Highway 403 was
completed and opened to traffic from the Highway 2 & Highway 53 Junction at Cainsville just east of Brantford to Highway 2 southeast of Paris. In the
mid-1970s, the Brantford Bypass section of Highway 403 was extended west across the Grand River to bypass Paris as well. This new section of Highway 403
opened to traffic between Highway 2 and Rest Acres Road (Highway 7094) in 1978.

In the late 1950s and early 1960s, the DHO undertook several planning studies, which identified a future need for a new east-west highway corridor
between Burlington and Toronto. The route that was eventually selected for this new highway branched off from the Queen Elizabeth Way and Highway 403
Interchange at Freeman and continued northeasterly towards Toronto. The necessary right-of-way for this highway was protected for future use, although
portions of the highway were not constructed until the 1980s. With the rapid development of Mississauga in the 1970s, the imminent need for this new
east-west highway corridor became apparent. The original intention was to link the proposed Mississauga section of highway with the existing
Burlington-Ancaster section of Highway 403. However, only the eastern section of the highway was needed at that time. A decision was made to temporarily
link Highway 403 into the Queen Elizabeth Way near the Ford Plant in Oakville. The first construction contract for Highway 403 through Mississauga was
commenced in 1977, although advance construction of the Highway 403 Interchange on Highway 401 had been underway since 1974. By 1980, Highway 403 had been
completed from Highway 401 to Highway 10 (Hurontario Street). In 1981, another section of Highway 403 opened from Erin Mills Parkway to the Queen Elizabeth
Way in Oakville. By 1982, the only incomplete section of the Mississauga leg of Highway 403 lay between Erin Mills Parkway and Highway 10. On December 2,
1982, this final section of the Mississauga leg of Highway 403 was completed and opened to traffic. In 1985, construction started on an advance contract to
extend Highway 403 west towards Burlington. The Trafalgar Road Connector (known internally by MTO as Highway 7197) was opened to traffic from Highway 403
to Trafalgar Road in 1989, as a two-lane staged freeway. The Trafalgar Road Connector was later incorpoated into the route of Highway 407.

In 1980, work began on the first of a series of construction contracts to extend Highway 403 from Highway 7094 (Rest Acres Road) to Highway 401 in Woodstock.
The first section of this new extension was opened in 1983 between Rest Acres Road and Brant Road 25. Highway 403 was completed and opened to traffic from
Brant Road 25 to Highway 53 at Eastwood in late 1985. Construction began on the final section of Highway 403 between Highway 53 and Highway 401 in
Woodstock in 1986. The new Highway 401 & Highway 403 Interchange in Woodstock was completed and opened to traffic in mid-1988. With the completion of
the Brantford-Woodstock section of Highway 403 in 1988, the Ministry of Transportation (MTO) turned its attention to completing the Brantford-Ancaster
section of Highway 403. Construction began in 1990, and work slowly progressed until 1996. The entire Brantford-Ancaster section of Highway 403 was
completed and opened to traffic in August, 1997.

The completion of the Brantford-Ancaster section of Highway 403 resulted in a single, continuous through route from Highway 401 in Woodstock to the Queen
Elizabeth Way in Hamilton. However, the MTO was still faced with the dilemma of the discontinuous eastern leg of Highway 403 through Mississauga. The
right-of-way that had been set aside for the new east-west highway corridor back in the 1960s had been leased off to the Highway 407 Express Toll Route
Consortium in the interim years. Highway 407 ETR was quickly built on this land during the late 1990s, destroying any possibility of uniting the
discontinuous eastern portion of Highway 403 with the remainder of the highway. The only simple solution was to sign Highway 403 concurrently with the
Queen Elizabeth Way through Burlington and Oakville. The MTO decided to do just that, and since December, 2002, the Queen Elizabeth Way has been signed
concurrently with Highway 403 between Exit #100 and Exit #123.

The entire highway from Woodstock to Hamilton is four lanes, with two lanes provided for each direction of travel. From Oakville to Downtown Hamilton, six
through lanes are provided (3 per direction). The Mississauga section of Highway 403 varies from four to ten general purpose lanes. The short ten-lane
section from Eglinton Avenue to Highway 401 was constructed in a collector-express lane configuration. Ontario introduced High-Occupancy Vehicle (HOV)
Carpool Lanes through Mississauga in December, 2005. There is one HOV lane in each direction from Highway 407 to Highway 401. The HOV Lanes are for the
exclusive use of public transit vehicles and passenger vehicles with at least two occupants. Transport trucks are prohibited from the HOV Lanes, as are
passenger vehicles with only one occupant. The intention of these HOV Lanes is to ease traffic congestion by encouraging public transit use and carpooling.
Drivers who violate the minimum occupancy requirements of the HOV Lanes are subject to a fine of $110.00 and 3 Demerit Points under the Ontario Highway
Traffic Act. The HOV Lanes on Highway 403 have been a great success. The lanes now carry an average of over 1,100 vehicles per hour during peak travel
periods. Future HOV Lanes are planned along Highway 403 between Mississauga and Hamilton.

There are no Service Centres located along Highway 403, but services are available at most exits. The posted speed limit on Highway 403 is 100 km/h
(60 mph), except from Highway 6 North to Main Street in Hamilton, where the posted limit is 90 km/h (55 mph). Exits along Highway 403 are numbered based on
their distance from Highway 401 at Woodstock. Approximate distances along the highway can therefore be calculated by subtracting one exit number from
another. For example, the distance from Highway 24 South (Exit #27) to Highway 6 North (Exit #74) is 47 km (74 - 27 = 47). Please visit the
Highway 403 Mileage Chart page for a list of interchange numbers along Highway 403.